LGNPC isn't something I want to consider as there can be some bad conflicts, right?

I still wish for a levitation animation replacer, I remember it cant be done, so... http://youtu.be/YGzqbEeVWhs

Its still a WIP and yes there are bugs but hopefully they get fixes soon.

No more than most other mods and a whole lot less than some. The only mod that I know of off-hand that it'll conflict with is Vampire Embrace, but there's a work around for that. I've played with 80+ mods and the only issue I've had that's even close to a conflict was with the Seyda Neen version, but the author of that mod made a few changes he shouldn't have like changing the gender of the Silt Strider driver. The other mods don't do things like that.

LGNPC really only conflicts with its own various modules (Ald'ruhn / Pax Redoran / Vivec Redoran especially) so most of the bugs can be ignored or worked around. I'm running all of them with about 170 other mods and, other than the transgender silt strider driver Jac mentioned, I haven't noticed any other issues with it.

Oblivion introduced separate worldspaces for exactly that purpose. It elevates that "interior acts as exterior" hack for Tribunal into a regularly used feature. Skyrim more or less uses that method, as well.
So it's not something that Oblivion lacks, it just handles it differently.

I'd like a mod that detects player gender and adjusts some of the guild/house rank names accordingly. I know it's nitpicking, but it would be nice to see.

I would like a mod that adds more Tapestries that are actually lore correct.

I wish flames, ligtning bolt spell in Morrowind.

http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=9412 might be of interest to you.